1. Field of the Invention
This invention relates to improvements in mechanisms for operating drop-bolt-type lock assemblies.
2. Prior Art
It is known in the art that drop-bolt locks (also known as vertical dead bolts) provide extremely good resistance to defeat by jimmying, chiseling, prying and the like.
Drop-bolt locks of jimmy-proof construction utilizing a pair of rings on a strike or keeper for a pair of bolts operated by rotational action of a lock cylinder from either side of the door are also known in the art. Such are sold under the trademark Segalock by the New England Lock and Hardware Co. of South Norwalk, Conn. However, such locks leave something to be desired in the smoothness of the operability of the bolt as they are operated from a hinged pin and lever arrangement. For example, see U.S. Pat. No. 1,922,043 granted 1933. The components are not particularly easy to service as they will sometimes fly apart when attempting to disassemble.